AUTHOR=Zheng Xiang-Rong , Zhang Mao-Jiao , Qiao Yu-Hang , Li Ran , Alkan Noam , Chen Jie-Yin , Chen Feng-Mao 

TITLE=Cyclocarya paliurus Reprograms the Flavonoid Biosynthesis Pathway Against Colletotrichum fructicola

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.933484

DOI=10.3389/fpls.2022.933484

ISSN=1664-462X

ABSTRACT=<p><italic>Cyclocarya paliurus</italic> is an endemic Chinese tree species with considerable medicinal, timber, and horticultural value. The anthracnose disease of <italic>C. paliurus</italic> is caused by the fungal pathogen <italic>Colletotrichum fructicola</italic>, which results in great losses in yield and quality. Here, resistance evaluation of six cultivars of <italic>C. paliurus</italic> exhibited varying degrees of resistance to <italic>C. fructicola</italic> infection, where Wufeng was the most resistant and Jinggangshan was the most susceptive. Physiological measurements and histochemical staining assays showed that the Wufeng cultivar exhibits intense reactive oxygen species accumulation and defense capabilities. A multiomics approach using RNA sequencing and metabolome analyses showed that resistance in <italic>C. paliurus</italic> (Wufeng) is related to early induction of reprogramming of the flavonoid biosynthesis pathway. <italic>In vitro</italic> antifungal assays revealed that the flavonoid extracts from resistant cultivars strongly inhibited <italic>C. fructicola</italic> hyphal growth than susceptible cultivars. Relative gene expression analysis further demonstrated the pivotal antifungal role of <italic>C. paliurus</italic> flavonoids in targeting <italic>Colletotrichum</italic> appressorium formation. Together, these results represent a novel resistance mechanism of <italic>C. paliurus</italic> against anthracnose through the reprogramming of flavonoids, which will lay a foundation for breeding anthracnose-resistant varieties and the application of flavonoid extraction of <italic>C. paliurus</italic> as a natural antifungal treatment.</p>